Safety razor blade



May18,193-7. w. 'FIRNEBURG l 2,080,860

SAFETY RAZOR BLADE Filed Sept. 26, 1936 Patented May 18, i937 Unirse srt orales SAFETY nAzoa BLADE Wilhelm Firneburg, Motherwell, Scotland, as-

signor to Clyde Blades Limited, Lanarkshire,

Scotland 3 Claims.

This invention relates to laminar razor blades formed of resilient metal and having one or two longitudinal cutting edges.

In the specification of U, S. A. Patent No. 1,971,985, safety razor blades of this type are described as being buckled or otherwise formed in such manner that when clamped in a razor blade holder, the cutting edge, or edges, is, or are, placed under greater tension than the remainder of the blade.

Various forms of blades are described in said specification, but diiculty is found in practice in devising a cheap and simple method of forming the waves or undulations which will produce the necessary tension in the cutting edge, or edges.

The invention has for its object to provide a new and improved method of manufacturing such blades.

According to the present invention a laminar safety razor blade is formed by two parts, one part, hereafter referred to as the outer part, comprising the two longitudinal edges, one or both of which is or are sharpened, and the two ends of the blade, and the other part comprising the centre of the blade which is buckled or otherwise distorted and then welded or otherwise secured to the first part at its ends.

Preferred embodiments of the invention and the method of making same will now be described with reference to the annexed drawing, wherein:-

Figure 1 is an elevation of a blade in accordance with the invention, this figure being shown to a larger scale.

Figure 2 is a plan View thereof.

Figure 3 illustrates a step in the manufacture of one of the parts of the blade.

Figures 4 and 5 are plan views of the two parts of the blade.

Figure 6 is a plan view of a modified construction of blade in accordance with the invention, and

Figures 'l and 8 are plan views of the two parts of the blade shown in Figure 6.

Figure 9 is a planview of a blade of the slotted type in accordance with the invention, and

Figures 10 and 11 are plan views of the two parts of the blade shown in Figure 9.

In carrying the invention into effect according to the construction shown in Figures 1 to 4, a blank a, having three holes b, c and d, is taken and portions of the blade e and f are punched or stamped out so as to leave the two end holes b and d surrounded by metal and also leave a strip of metal g, see Figure 3, which joins the two longitudinal edges It and i and contains the centre hole c.

'Ihe blank is then hardened, tempered and ground, the cutting edges formed by the outer edges of the strips h and z' completely finished, and then the bridge piece g is removed, thus leaving a long narrow longitudinal strip at each side, said strips having cutting edges.

The bridge piece is provided to support the longitudinal edges during the sharpening operations.

A blank j, see Figure 5, is then provided for the centre portion of the improved blade, which blank has three holes 7c, l and m made therein,

but the distance apart of the two end holes lc and m is slightly greater than the distance apart of the holes b and d in the part al. This centre portion is then slightly bent or buckled in the direction of its length, see Figure 1, and tempered so as to have a spring therein, It is made narrower than the slot in the other portion, and is placed therein in such manner that the two end holes lc and m coincide with the end holes b` and d in the outer portion. In this position'it is spot welded to the outer portion at a point or points in proximity to each end hole, the points being preferably on a line passing through the centres of the two end holes, as indicated at n. If desired, more than two spot welds may be made at each end and in other convenient positions than described.

The bent or buckled portion must overlap the outer portion at the ends only and not at the longitudinal sides.

In the method above set forth the bridge piece joining the edges is retained solely for the purpose of facilitating the sharpening process. If desired, however, the centre portion may be cut or punched so as to leave no bridge piece. To facilitate the removal of the bridge piece the surface of the blank a may be cut along the lines where the bridge piece joins the edges h and z' as indicated by the dotted lines g1, this being done prior to the hardening process.

In the construction shown in Figures 6, '7 and 8 the blank al has its centre stamped or punched out so as to leave the two longitudinal strips h1 and 111 and end portions o` and p, see Figure 7, the outer edges of said strips constituting the cutting edges. The blank is hardened, tempered and ground and the cutting edges formed by the outer edges of said strips completely finished. If desired, a bridge piece, equivalent to the bridge piece g, Figure 3, may be left joining the strips h1 and i1 until said operations are completed and thereafter removed.

The centre portion jl, see Figure 8, is slotted, as shown, then slightly curved, similar to the corresponding portion y', Figure l, and tempered so as to leave a spring therein. The part a1 is then placed over the part jl and welded thereto as at nl. This blade then presents the same appearance in elevation as shown in Figure l.

In the construction shown in Figures 9, 10 and 11 the construction and method of making the blade is similar to that described with reference to Figures 6, 7 and 8 except that the shape of the blank a and the stamped or punched out portion are different and the centre portion :i2 which is welded to the blank a at its ends is provided with a slot i3 to suit holders with longitudinal ribs.

The centre part need not be curved as illustrated, but may be undulated or Otherwise formed so that when the blade is clamped in its holder said part tends to flatten out and thereby places the two longitudinal edges of the blade under tension.

It will be further understood that both the outer portion and centre portion of the blade may be altered in shape as may be desired to suit the razor holder or to enhance or improve the appearance of the blade.

The outer portion of the blade may be slightly recessed by stamping or otherwise partly to accommodate the ends of the centre portion which is welded thereto.

Instead of the parts being welded together they may be secured to each other by brazing, soldering or riveting.

What I claim isz- 1. A laminar safety razor blade formed by two parts, one part comprising the two longitudinal edges, one or both of which is or are sharpened, and the two ends of the blade, and the other part comprising the centre of the blade which is buckled or otherwise distorted and then welded or otherwise secured to the first part at its ends.

2. A laminar safety razor blade comprising an outer part formed by two longitudinal edges, two ends and a centre part buckled or otherwise distorted and secured at its ends by welding to the two ends of the outer portion.

3. A laminar safety razor blade comprising an outer part formed by two longitudinal edges, two ends and a centre part buckled or otherwise distorted and having one or more openings therein to suit a razor blade holder, the centre portion being welded at its ends to the ends of the outer portion.

WILHELM FIRNEBURG. 

